Cribbage Board #10: The Wedding Board

WEDDING BOARD PICTURES

About These Files:

Whenever I complete a project, I always wish I had taken more pictures. The same holds true for The Wedding Board, as I wish I had more photos of the manufacturing process. On the other hand, endless hours of sanding and soldering just don't translate into inspiring photographic subjects. I've grouped the photos into 3 rough sets below. Eventually I might add a slide-show.

Concept Phase

Scans of some of the notebook sketches in the early phase of the Wedding Board. A lot of the design decisions and directions were made during this period.

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6/12/2000 Although I started work a little earlier, this is the earliest sketch page in my normal notebook. Notice the main though to use the LEDs as pegs. The rest of the page is devoted to figuring out how an LED would reliably and repeatedly make connections as it is "pegged". Additionally, how would one prevent the LED from being hooked up backwards (thereby frying it).

6/12/2000, part 2 More thoughts on construction. Possibility of using an LED with an integral resistor. Possible board construction.

6/18/2001 A year later (the project had been shelved for awhile in order to work/finish on numerous other things...totems...etc etc) and after significant back-burner thought, these notes were written up to give a little history into the thought process. The bottom part of the page starts to explain where the colorwash concept came from.

6/19/2001 This page maps out the PWM control of the RGB LEDs. This is the basis for the colorwash sequence. The question here: How to fit this into a cribbage peg?

6/19/2001, part 2 (Note, the date on some of these pages is actually wrong). Going through the thought-process for how to colorwash a peg. On-peg or off-peg intelligence? Serious thought was given to off-board intelligence. However, after firsthand testing of the physical connection, it was deemed unpleasant to repeatedly peg with any of the 4-conductor connectors.

6/19/2001, part 3 Exploration into on-peg intelligence. Testing actual connectors verified that pegging with a typical RCA jack was acceptable. Numerous RCA plug bodies were tested for peg-ability. Additionally, Mouser happened to have a supplier with non-standard RGB phono sockets. To sweeten the deal even more, Mouser also had RCA connectors with Red, Blue, and Yellow (re-anodized to green for the final product) anodized connectors. Since these particular connectors pegged with too much force, a combination of connector base and body was settled on for the final product. (Cheap connectors peg much better and use nickel plating instead of gold).

6/19/2001, part 4 Continuing to explore on-peg intelligence. Turns out the 6 pin RGBB LED straddles a .030" thick PCB perfectly (makes assembly easier). However, this part uses a common cathode and the smallest Atmel processor (the Tiny12) can't source that much current. It was clear that small FETs (easier to control with PWM pulses) would be needed.

The choice to use FETs proved a fortunate one. The tiny Peg board is capable of sourcing quite a bit of current and has become a very handy development board.

12/12/2001 Several months later, I was trying to figure out how to assembly the groups of 5. One of the main concerns (besides manufacturability) was long term survivability (and even archivability). The Groups of 5 needed to be replaceable should they ever wear out. Modular sub-assembly builds of Groups of 5 meant that they would need to be easily connected and replaced. Wires are ugly. Interconnection boards became the chosen solution. This required extensive modeling in SolidWorks with very careful translation of dimensions into Protel to make sure every connector ended up where it needed to be. And it all worked the first time!

The bottom half of the page has the existential moment of the project.....

12/26/2001 Manufacture of the top zirocote frame. A lot of thought was put into how the wood-grain would look with various assembly options.

12/27/2001 A quick sketch of a group of 5 PCB.

2/21/2002 Several months later, a little though to how to switch between battery and DC power.

11/23/2002 A long time later, it was time to start understanding the basis behind the colorwash code that Shannon was putting together. This page is a visual depicton of some of the vocabulary used. For a better explanation, check out this document....

Design

Most of the SolidWorks design work is shown in the videos and other documents. Most of the Protel design work is in the schematics area. Regardless, here are a few still-shots.

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Here's a picture of the infamous Fridge Door Switch. This picture shows some of the detail that went into the 3D solid modeling (SolidWorks). This micro switch detects when the lid is openend and applies power to the pegholder rail (quite the stunning effect). This last minute addition was the ultimate in decadent feature creep.

For more images of the solid modeling, go to the Movies page, where you'll be able to see the models rotated.

Here's a screen shot of the PCB layout for the Peg. The PCB work was done in Protel (now owned by Altium). In order to fit inside the RCA jack, the peg pcbs had to be made from .015" thick material.

This is a screen shot of the Programmer Board PCB layout.

To save some money during this project, the boards were purchased tiled in an unrouted panel. They were then sawn apart in my workshop using a bandsaw. This significantly reduced the cost for typically associated with all of the custom PCB routing. I used QualTech Circuits for numerous reasons.

Construction

Woodwork

The Wedding Board is equally about the woodwork and the electronics. The best materials were used and taken to the highest level of finish. Easily maintained finish oils and waxes were chosen over high gloss (stripping-required to re-finish) varathanes. Archival quality...

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The bottom of the board was designed to be made from a single piece of solid maple. After taking the block wood to Minton's Lumber to plane it to thickness, it was time to mill the features. This was done by me on a Bridgeport Mill. This photo shows the end result of milling two maple bodies (and 10 pounds of sawdust). For you eco-folks, don't worry, the sawdust was recycled in the form of smoked fish.

Turns out the Bridgeport didn't have enough z-axis travel for milling the 3/4" power switch hole. For this, a "fancy" setup was required. Back in my shop, I employed my drill press, handy workbench and a couple of clamps to get-r-done.

The milling and drilling was followed by 3 months of intense sanding. All of the wood pieces (maple and zirocote) were brought from 150 all the way to 400 grit (dry). Then, wet sanded with the finishing oil with 400, 600 and 1000 grit. Finally, a layer of satin finishing wax was applied and buffed out at 1000 grit and #0000 scotchbrite. Baby's bottoms wish they could be this smooth.

So much work went into the sanding, it's worth another photo. Check out that figure in the maple. The power switch is a piece of zirocote (same as the top frame).

Here's a closeup of the zirocote top frame with the groups of 5 and plastic shield mounted. The top-frame was made from 4 individual pieces of zirocote with precise mitred corners. The frame was clamp-glued together with polyurethane glue and is bolted to the top aluminum panel for additional strength. Both the top frame and maple body were match routed to the aluminum top to achieve the 1/4" corner fillet.

This view shows a little more of the electronics interconnects and groups of 5. To fit everything in (hinges, PCBs, connectors, wires) it all had to be modeled in SolidWorks.

Speaking of the top frame. This view shows the numerous RGB connectors mated to the the top aluminum panel. The bolts around the edge mate directly with the zirocote frame.

Electronics

The electronics were designed, not simply laid out. Attention was paid to the visual impact the exposed PCBs would have on the final product. In spite of the significant increase in cost, the PCBs used Red, Green and Blue solder mask (red for interconnects, blue for Groups, Progammer, Pegholder, and green for Peg PCBs).

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This photo provides a great transition from the woodworking discussion. The peg and associated PCB and ICs were modeled to the finest detail to ensure fin in the RCA plug body. Even the 0402 resistor packages were included. This photo shows a "naked" peg being held in the programmer board. To illustrate the completeness of the sanding, notice the reflection of the programmer board on the far wall of the milled pocket. Yes, in my sanding insanity, I even wet sanded and finished the surface hidden by the Programmer Board PCB itself....

Here's a view of a Programmer Board prior to inclusion into the assembly. In order for everything to line up and fit (the Programmer Board is mechanically over-constrained) the power switch, DC jack, RCA sockets and power pins had to all be modeled. This photos shows the "user interface" for programming pegs (3 simple steps). You'll also note that the Programmer Board and the Peg share numerous common parts (ATTiny12, ISP socket, FETs)...this is intentional.

This is just a great closeup of the "frontside" of a Peg. Up front and center is the heart of the beast, the Atmel ATTiny12. Electronics buffs will note that the SO-8 package has been "J-leaded" to fit. Above the Tiny12 are the 2 dual-FET drivers. Above these guys are the 4 0402 resistor packages. Finally, at the very top is the unusual, but groovy, Kingbright RGBB LED (6-pin package).

Compared to the front side of the Peg, the back side has a ton of room. At the very bottom we have a pullup resistor (blue package) hidden under the ground connection of hte RCA jack. Right above that is the very important .1uF decoupling cap. Above that is the all-important 6-pin ISP connector. This connector is 2mm pitch and is the smallest, lowest profile 6-pin connector readily available. The ability to In System Program the ATTiny12 allows the pegs to be used for multiple purposes, and for firmware upgrades to occur on the finished product.

Lots and lots of Pegs were made. All told, I have constructed approximately 100 Pegs over the last 4 years. Here's 32 of them in different stages of construction. Each of the 3 Wedding Boards shipped with 10 pegs (9 for playing, 1 for showing off the inside).

Speaking of ISP (In System Programming). Here's a shot of the computer, the AVRISP , the custom ISP cable, the target Peg and a Wedding Board providing power. In the background is the box from the Atmel starter kit (the STK500)

Wanna see a closeup of what an Peg being programmed looks like? Weird huh? Feels naked and small with a big life-support cable hanging from it. This is also a good shot of the top of the board.

Finished

The finished Wedding Board almost hides the complexity and effort that went into its creation. This translates into elegance.

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This is it! Ain't it pretty? Notice the quilting on the maple and the reflection on the nickel plated aluminum.

One of my favorite photos of the Wedding Board. From the figure in the maple, to the gleam off the nickel plated lid support, it brings a tear to my eye. The scratch-free polycarb panel and the sea of connectors behind (always show one's work) illustrate the effort and focus required to control the complexity of such a project and bring it together with elegance.

Proof, for insurance purposes! Yes, three completed boards. On the bottom right of the photo is the first version of the "Instructions Manual". The second version o of the Instructions Manual is the size of a deck of cards (and 52 pages long) and fits next to the deck of cards. In the leftmost pocket is the AC to DC power adapter (for running the board for longer periods of time.). You'll also note the lide is held open by the lid-support (far left of each board). Just to the right of the peg holder area is the battery pocket. Each board has two sets of 4 AA batteries. The two sets are in parallel and allow the board to run on battery power for >24 hours (depending on number of players and peg modes chosen).

A picture of the first fully-assembled board on my workbench.

I could not have done it without the equipment (and mess) shown in the background. Incidentally, to prove how much of a geek I really am, this workbench resides in my bedroom. Thank you, workbench.

A really great shot of the programmer board in its pocket and the batteries in theirs. Note the method (setscrew) and mounting of the power switch. The zirocote (seen from outside) was laminated onto a 3/4" poplar dowel and turned (on a lathe) down to precise size. This piece is setscrewed in place onto the main power switch. This view also shows the implementation of the fridge door switch, the barrel hinges and the method of interconnecting all the power.

Speaking of power, here's the bottom view of a board. The DC power connector goes through a hole in the maple and mates with the jack on the Programmer Board. The pocket was made with a 2" diameter forstner bit. Also note the wire channel to ensure the board sits flat when plugged in.